Motor assembly and vacuum cleaner having the same

ABSTRACT

A motor assembly includes: a motor including at least a motor body and a motor blade portion; at least one inner motor casing configured to enclose at least a part of the motor; and at least one outer motor casing configured to enclose at least a part of the at least one inner motor casing, wherein air in the motor is caused to change direction when passing along at least one of the at least one inner motor casing and the at least one outer motor casing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. §119 from Korean Patent Application No. 2005-40203, filed May 13, 2005, the entire contents of which are incorporated herein by reference. This application may also be related to commonly assigned U.S. patent application Ser. No. 10/851,243, filed May 24, 2004, U.S. patent application Ser. No. 11/206,905, filed Aug. 19, 2005, as well as to attorney docket no. 116511-00202, entitled “MOTOR ASSEMBLY AND VACUUM CLEANER HAVING THE SAME”. The contents of each of these three applications are incorporated herewith.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a vacuum cleaner, and more particularly, to a motor assembly configured to reduce noise generated in a motor and a vacuum cleaner having the same.

2. Description of the Related Art

A vacuum cleaner draws in dust using a suction force generated by a motor and collects the dust in a dust collecting chamber. The vacuum cleaner employs a high output motor having a high number of RPMs. However, such a high output motor causes a large volume of noise when it is driven.

Korean Patent Publication No. 1997-32650 describes a motor casing including a noise absorbing member and a noise blocking member. The noise blocking member encloses the noise absorbing member and has diffusion perforations formed on a surface thereof. Japanese Patent Publication No. H01-268524 describes a motor casing including a first penetrating hole formed on a side surface, a second penetrating hole formed on a rear surface, and a noise absorbing member disposed at the first and the second penetrating holes.

However, since the disclosures of the Korean Patent Publication No. 1997-32650 and Japanese Patent Publication No. H01-268524 require the extra noise absorbing member to reduce noise, their structures are complicated and their manufacturing cost is high.

Also, although both disclosures can reduce a blade passing frequency (BPF) and the entire noise level, they do not effectively reduce a low frequency band noise.

SUMMARY OF THE INVENTION

The present invention has been developed in order to solve the above problems in the related art. A first aspect of the present invention is to provide a motor assembly having a simplified configuration and a vacuum cleaner having the same.

To this end, the present invention provides a motor assembly that includes: a motor including at least a motor body and a motor blade portion; at least one inner motor casing configured to enclose at least a part of the motor; and at least one outer motor casing configured to enclose at least a part of the at least one inner motor casing, wherein air in the motor is caused to change direction when passing along at least one of the at least one inner motor casing and the at least one outer motor casing.

Another aspect of the invention provides a vacuum cleaner that includes: a cleaner body including at least a dust collecting chamber and a motor chamber; a brush assembly configured to be connected to the dust collecting chamber; a motor disposed at the motor chamber and including at least a motor body and a motor blade portion; at least one inner motor casing configured to enclose at least a part of the motor; and at least one outer motor casing configured to enclose at least a part of the at least one inner motor casing, wherein air in the motor is caused to change direction when passing along at least one of the at least one inner motor casing and the at least one outer motor casing.

Another aspect provides a motor assembly, which includes: a motor; at least one inner motor casing configured to enclose at least a part of the motor; at least one outer motor casing configured to enclose at least a part of the at least one inner motor casing; and means for changing a direction of air flow between the at least one motor casing and the at least one outer motor casing.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a view schematically illustrating a cleaner body in which a motor assembly according to a non-limiting embodiment of the present invention may be mounted;

FIG. 2 is a view illustrating the motor assembly of FIG. 1, in which a contour line of an outer motor casing is expressed by a dashed line such that only an inner motor casing is shown;

FIG. 3 is an exploded perspective view illustrating the motor assembly of FIG. 2; and

FIG. 4 is a graph illustrating a noise reduction effect achieved by the motor assembly according to a non-limiting embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a motor assembly and a vacuum cleaner having the same according to a non-limiting embodiment of the present invention will now be described with reference to the accompanying drawings. For reference, arrows in the drawings indicate an air flow direction.

FIG. 1 is a view illustrating a cleaner body in which a motor assembly according to a non-limiting embodiment of the present invention is mounted. Referring to FIG. 1, the cleaner body 10 may include a dust collecting chamber S1 and a motor chamber S2.

The dust collecting chamber S1 may be a space that may be partitioned from the motor chamber S2 by a partition 10 a and may be formed in a front portion of the cleaner body 10. The dust collecting chamber S1 may have a dust collector to separate and collect dust. In this embodiment, a dust bag 11 may be provided as the dust collector. Instead of the dust bag 11, a single or multi-cyclone dust collecting apparatus (capable of being used repeatedly) may be provided in the dust collecting chamber S1.

A suction pipe 12 may be disposed at an upper portion of the dust collecting chamber S1 and may protrude to the outside of the cleaner body 10 as well as to the inside of the cleaner body 10. Dust may be drawn in through the suction pipe 12. The suction pipe 12 may be connected to a flexible hose 14 outside the cleaner body 10 and to the dust bag 11 inside the cleaner body 10. The flexible hose 14 may be connected to a brush assembly (not shown) through an extension pipe (not shown). The brush assembly may draw in dust from a cleaning surface therethrough.

According to the above-described configuration, the dust drawn in through the brush assembly (not shown), the extension pipe (not shown), the flexible hose 14, and the suction pipe 12 may be collected in the dust bag 11, whereas the air may escape from the dust bag 11 in the direction of arrow and may flow into the motor chamber S2 through a filter 40.

The motor chamber S2 may include a space that is partitioned from the dust collecting chamber S1 by partition 10 a and may be formed in a rear portion of the cleaner body 10. The motor chamber S2 may include a first motor chamber S21 and a second motor chamber S22.

The first motor chamber S21 may be enclosed by an upper wall 10 b and a side wall 10 c and may be located in front of the second motor chamber S2. A motor assembly 19 may be disposed in the first motor chamber S21. A motor 20 may use a high-output motor capable of generating a high number of revolutions per minute (RPMs). The high output motor may generate a large volume of noise when it is driven. In order to reduce the noise, the motor assembly 19 may be provided in the first motor chamber S21. The second motor chamber S22 may be formed in the rear portion of the motor chamber S2 by the side wall 10 c.

A discharge pipe 16 may be disposed at a rear upper portion of the motor chamber S2 to discharge the air to the outside therethrough. A discharge filter 30 may be disposed in an outlet of the discharge pipe 16 to filter dust included in the air.

Referring to FIGS. 2 and 3, the motor assembly 19 according to an embodiment of the present invention may include the motor 20 which may include a motor body 20 a and a motor blade portion 20 b. A motor casing 100 may also be provided to enclose the motor 20 and may include an inner motor casing 110 and an outer motor casing 120. The configuration of the motor 20 may be similar to those known to those of skill in the art.

The inner motor casing 110 may enclose the motor body 20 a and may be spaced away from the motor body 20 a by a predetermined distance such that a first air passage P1 (see FIG. 1) may be formed between the motor 20 and the inner motor casing 110. A plurality of first air passing holes 110 a may be formed along a circumference of the inner motor casing 110. The inner motor casing 110 may include a first securing protrusion 111 formed at a circular edge of the inner motor casing 110 and may include a first securing hole 110 b through which a screw is inserted. The outer motor casing 120 may include a front casing 121 and a rear casing 122, which may be separable from each other.

The front casing 121 may enclose the motor blade portion 20 b and may have a second securing protrusion 121 b formed at a circular edge of the front casing 121 to be connected to the rear casing 122. The securing protrusion 121 b may include a second securing hole 121 bb corresponding to the first securing hole 110 b of the first securing protrusion 111.

The rear casing 122 may enclose the inner motor casing 110, which may be spaced from the inner motor casing 110 by a predetermined distance such that a second air passage P2 (see FIG. 1) may be formed between the inner motor casing 110 and the rear casing 122. The rear casing 122 may have a plurality of second air passing holes 122 a defined on a surface (e.g., a rear surface) of the rear casing 122 in a radial direction. The second air passing holes may be omitted from the center of the rear casing 122. Of course, the arrangement of the second air passing holes 122 a may extend to the center of the rear casing 122.

The rear casing 122 may have a third securing protrusion 122 b formed at a circular edge thereof to be connected with the front casing 121. The third securing protrusion 122 b may include a third securing hole 122 bb corresponding to the first and the second securing holes 110 b, 121 bb of the first and the second securing protrusions 111, 121 b.

Although the inner motor casing 110 may enclose only the motor body 20 a in this non-limiting embodiment, it may also be designed to enclose the motor blade portion 20 b as well as the motor body 20 a. Also, the outer motor casing 120 may be designed to enclose the entire motor 20 or to enclose only the motor body 20 a. Also, variations of the air channel are possible. For example, two or more outer motor casings 120 may enclose the inner motor casing to reduce noise.

Referring to FIG. 1, when the air escapes from the motor 20, it may be deflected by the first air passage P1, may pass through the first air passing holes 110 a, may again be deflected by the second air passage P2, and then may pass through the second air passing holes 122a. At this time, the air may change its direction when it flows from the first air passage P1 to the second air passage P2. For example, the air may change its direction by substantially 90° to 180° when it flows into the second air passage P2 from the first air passage P1.

When the air is deflected by the first air passage P1, passes through the first air passing holes 110 a, is again deflected by the second air passage P2, and then passes through the second air passing holes 122 a, its flow velocity changes. Also, when the air changes its direction as it flows from the first air passage P1 to the second air passage P2, noise is reduced.

FIG. 4 is a graph illustrating a noise reduction effect achieved by the motor assembly. Referring to FIG. 4, noise is measured as 73.5 dBA if the motor assembly 19 is provided, whereas noise is measured as 78.7 dBA if there is no motor assembly 19. In other words, the noise is reduced by as much as 5.2 dBA. The amount of noise reduction is large in a low frequency band (0˜2000 Hz).

Hereinafter, the operation of the vacuum cleaner employing the motor assembly 19 will now be described. Referring to FIG. 1, a suction force is generated when the motor 20 is driven, and dust is drawn in through the brush assembly (not shown), the extension pipe (not shown), the flexible hose 14, and the suction pipe 12 by the suction force, and collected in the dust bag 11.

Cleaned air escapes from the dust bag 11 and flows into the motor 20 disposed in the first motor chamber S21 after passing through the filter 40. When the air escapes from the motor 20, it is deflected by the first air passage P1 by 90°. Then, the air passes through the first air passing holes 110 a, is again deflected by the second air passage P2, and then passes through the second air passing holes 122 a. After that, the air may be discharged from the cleaner body 10 through the second motor chamber S22, the discharge pipe 16, and the discharge filter 30.

According to the present invention as described above, the motor assembly 19 and the vacuum cleaner having the same have the following advantages.

First, since the motor assembly 19 may include the inner motor casing 110 having the first air passing holes 110 a and the outer motor casing 120 having the second air passing holes 122 a, and may not require an extra noise-absorbing member, the motor assembly 19 has a simplified configuration and its manufacturing costs decrease.

Second, the air changes its flow velocity while being deflected by the first air passage P1, passing through the first air passing holes 110 a, being again deflected by the second air passage P2, and then passing through the second air passing holes 122 a. Also, since the air changes its direction while moving from the first air passage P1 to the second air passage P2, a noise is reduced. Especially, a low frequency band noise is effectively reduced. Accordingly, a user can clean without much noise.

The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. Also, the description of the embodiments of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. 

1. A motor assembly, comprising: a motor including at least a motor body and a motor blade portion; at least one inner motor casing configured to enclose at least a part of the motor; and at least one outer motor casing configured to enclose at least a part of the at least one inner motor casing, wherein air at the motor is caused to change direction when passing along at least one of the at least one inner motor casing and the at least one outer motor casing.
 2. The motor assembly as claimed in claim 1, wherein the air is caused to change direction by substantially 90° to substantially 180° when flowing from a first air passage formed between the motor and the at least one inner motor casing to a second air passage formed between the at least one inner motor casing and the at least one outer motor casing.
 3. The motor assembly as claimed in claim 1, wherein the at least one inner motor casing is configured to enclose the motor body of the motor, and the at least one outer motor casing is configured to enclose the motor body and the motor blade portion.
 4. The motor assembly as claimed in claim 3, wherein the at least one inner motor casing and the at least one outer motor casing each include a plurality of air passing holes to allow air escaping from the motor to pass therethrough.
 5. The motor assembly as claimed in claim 4, wherein the plurality of air passing holes include at least one first air passing hole defined at a circumference of the at least one inner motor casing and at least one second air passing hole defined at the at least one outer motor casing.
 6. The motor assembly as claimed in claim 5, wherein at least one second air passing hole is defined at a rear of the at least one outer motor casing,
 7. The motor assembly as claimed in claim 6, wherein the at least one first passing hole is defined around the circumference.
 8. The motor assembly as claimed in claim 5, wherein the at least one first passing hole is defined around the circumference.
 9. A vacuum cleaner comprising: a cleaner body including at least a dust collecting chamber and a motor chamber; a brush assembly configured to be connected to the dust collecting chamber; a motor disposed at the motor chamber and including at least a motor body and a motor blade portion; at least one inner motor casing configured to enclose at least a part of the motor; and at least one outer motor casing configured to enclose at least a part of the at least one inner motor casing, wherein air at the motor is caused to change direction when passing along at least one of the at least one inner motor casing and the at least one outer motor casing.
 10. The vacuum cleaner as claimed in claim 9, wherein the at least one inner motor casing and the at least one outer motor casing each include at least one air passing hole configured to allow air escaping from the motor to pass therethrough.
 11. The vacuum cleaner as claimed in claim 10, wherein the at least one air passing hole is formed at a rear of the at least one outer motor casing.
 12. The vacuum cleaner as claimed in claim 10, wherein the at least one outer motor casing is configured to entirely enclose the at least one inner motor casing.
 13. A motor assembly, comprising: a motor; at least one inner motor casing configured to enclose at least a part of the motor; at least one outer motor casing configured to enclose at least a part of the at least one inner motor casing; and means for changing a direction of air flow between the at least one inner motor casing and the at least one outer motor casing.
 14. The motor assembly as claimed in claim 13, wherein the means for changing changes the direction of the airflow between substantially 90° and substantially 180°.
 15. The motor assembly as claimed in claim 13, further comprising at least one air passing hole formed at at least one of the at least one inner motor casing and the at least one outer motor casing.
 16. The motor assembly as claimed in claim 15, wherein the at least one air passing hole includes a plurality of air passing holes.
 17. The motor assembly as claimed in claim 16, wherein a portion of the plurality of air passing holes is formed at the at least one inner motor casing.
 18. The motor assembly as claimed in claim 17, wherein a second portion of the plurality of air passing holes is formed at the at least one outer motor casing.
 19. The motor assembly as claimed in claim 17, wherein the at least one air passing hole of the second portion is provided at a rear portion of the at least one outer motor casing. 